In order to become a Give Lively nonprofit member, you must be a U.S. nonprofit public charity (not private foundation) with 501(c)(3) status and you need a GuideStar Nonprofit Profile. (GuideStar is now part of Candid.)
From GuideStar: "A GuideStar Nonprofit Profile is a web page displaying information on a single nonprofit organization. The data GuideStar has on nonprofits comes from the IRS Business Master File, IRS Forms 990/990EZ/990PF and from the nonprofits themselves. GuideStar Nonprofit Profiles are created using basic IRS information."
Claiming your profile is easy. Follow the directions provided by GuideStar to complete the process.